<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //利用递归求100的阶乘

        //100 * 99 * 98 * 97 * … * 1 = ?

        function fn(num){
            if(num == 1){
                return 1;
            }
           return num*fn(num-1);
        }
        var res = fn(100);
        console.log(res);

    </script>
</body>
</html>